1. Field of the Invention
The present invention relates to a switching device with an MIM (metal-insulator-metal) structure, comprising an organic insulating layer, and a method of preparing it. More particularly it relates to a switching device greatly improved in the repetition stability of switching characteristics and the switching speed, and a method of preparing it.
2. Related Background Art
Recently, there is an increasing interest in molecular electronics in which it is attempted to apply the functionality of organic molecules to electronic devices, etc. Studies on the Langmuir-Blodgett film (LB film) which may be deemed to be one of the constructive techniques for molecular electronic devices are being actively made. The LB film is formed by laminating organic molecule layers regularly one by one, and the film thickness can be controlled at a level of molecular length. Since a uniform and homogeneous ultra-thin film can therefore be formed, it has been frequently attempted to use such a film as an insulating film. For example, there are a tunnel bonding element with metal-insulator-metal (MIM) structure [G. L. Larkins et al., "Thin Solid Films", Vol. 99 (1983)]; emission element with metal-insulator-semiconductor (MIS) structure [G. C. Roberts et al., "Electronics Letters", Vol. 29, pp. 489 (1984)]; and switching element [N. J. Thomas et al., "Electronics Letters", Vol. 20, pp. 838 (1984)].
Although device characteristics have been solved, such device have the deficiency of reproducibility and stability such as variance in characteristics for every element and change with lapse of time.
Electrodes used in the studies mentioned above have hitherto been formed by vapor deposition using a mask. In instances in which electrodes are formed by the vapor deposition using a mask, the areas and shapes of electrodes can not be freely selected, and they are necessarily limited, causing problems, e.g., in preparing integrated circuits. On the other hand, if it is possible to freely select the areas and shapes of electrodes, an improvement could be expected in device characteristics or device-driving methods.